# US 5,283,698 A · Image reading apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,283,698 A - Document ID: US5283698A - Status: Granted - Kind: A - Application number: 07/863,782 - Filed: 1992-04-06 - Granted: 1994-02-01 - Earliest claimed: 1991-04-08 - Assignees: Canon Kabushiki Kaisha - Inventors: Nobumasa Fukuzawa; Akiyoshi Kimura - Web page: https://patentgrep.com/patent/US5283698A ## CPC - H04N 1/00013: {Reading apparatus} - H04N 1/00002: {Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for (error detection, error correction or monitoring in digital computers or digital computer components G06F11/00)} - H04N 1/00037: {Detecting, i.e. determining the occurrence of a predetermined state (H04N1/00031 takes precedence)} - H04N 1/00082: {Adjusting or controlling (interrupting an operation H04N1/00915; inhibiting an operation H04N1/00925)} - H04N 1/02409: {Focusing, i.e. adjusting the focus of the scanning head} - H04N 1/03: with photodetectors arranged in a substantially linear array - H04N 1/1013: {with sub-scanning by translatory movement of at least a part of the main-scanning components (H04N1/107 takes precedence)} - H04N 1/193: using electrically scanned linear arrays {, e.g. linear CCD arrays} - H04N 2201/02416: Rotational positioning, i.e. with respect to an axis - H04N 2201/02418: Rotation about the optical axis - H04N 2201/0242: Rotation about an axis in the plane of the scanning elements orthogonal to the optical axis, the axis of rotation extending in the main-scanning direction, e.g. the longitudinal axis of a linear array - H04N 2201/02429: Photodetector element, e.g. CCD array - H04N 2201/02431: Lens or optical system - H04N 2201/02441: using screws - H04N 2201/04703: using the scanning elements as detectors, e.g. by performing a prescan - H04N 2201/04715: by detecting marks or the like, e.g. slits - H04N 2201/0472: on or adjacent the sheet support - H04N 2201/04731: in the sub-scan direction - H04N 2201/04749: Detecting position relative to a gradient, e.g. using triangular-shaped masks, marks or gratings - H04N 2201/04755: by controlling the position or movement of a scanning element or carriage, e.g. of a polygonal mirror, of a drive motor - H04N 2201/04791: in the sub-scan direction - H04N 2201/04796: Varying the sub-scan control during the main-scan, e.g. for correcting skew, tilt or bow of a scanning beam - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract There is disclosed an image reading apparatus in which the scanning optical system having a slit is caused to scan in a short-side direction of the slit, and light passed through the slit and reflected from or transmitted through an original is guided to a solid-state image pickup element through an optical image forming element so that the image is formed on the solid-state image pickup element and is read. In the apparatus, opening portions for detecting a shift in relative positional relationship between the slit and the solid-state image pickup element are formed in both end portions of the slit in its longitudinal direction corresponding to a portion other than an effective image region of the solid-state image pickup element. ## Claims ### Claim 1 An image reading apparatus comprising: a line sensor; an image forming optical system for forming an image of an object on said line sensor; and a slit member disposed in an optical path between the object and said image forming optical system, said slit member having a slit and having opening portions at both end portions of said slit in a longitudinal direction thereof, said opening portions corresponding to portions outside an effective image region of said line sensor, and said opening portions being provided for detecting a shift in a relative positional relationship between said slit and said line sensor. ### Claim 2 (depends on 1) An apparatus according to claim 1, further comprising means for performing adjustment of said apparatus by moving said slit member on the basis of a result obtained by detecting light passing through the opening portions by said line sensor. ### Claim 3 (depends on 1) An apparatus according to claim 1, wherein said image forming optical system and said line sensor are constituted as a single unit. ### Claim 4 (depends on 3) An apparatus according to claim 3, further comprising means for performing adjustment of said apparatus by moving said unit on the basis of a result obtained by detecting light passing through the opening portions by said line sensor. ### Claim 5 (depends on 1) An apparatus according to claim 1, further comprising means for performing adjustment of said apparatus by moving the overall apparatus on the basis of a result obtained by detecting light passing through the opening portions by said line sensor. ### Claim 6 (depends on 1) An apparatus according to claim 1, wherein a width of each of said opening portions is smaller than a width of said slit in a direction of a shorter side of said slit. ### Claim 7 (depends on 1) An apparatus according to claim 1, wherein a non-opening portion is provided at a boundary between said slit and at least one of said opening portions. ### Claim 8 (depends on 1) An apparatus according to claim 1, wherein opposite ends of said slit in the longitudinal direction thereof have edges which are not parallel to edges of said opening portions. ### Claim 9 (depends on 1) An apparatus according to claim 1, further comprising masking members arranged on both end portions of said line sensor in the longitudinal direction thereof. ### Claim 10 (depends on 9) An apparatus according to claim 9, wherein each of said masking members comprises a slit having a width which is smaller than a width of the effective image region of said line sensor in a direction of a shorter side thereof. ### Claim 11 (depends on 1) An apparatus according to claim 1, wherein said line sensor comprises a plurality of reading picture elements. ### Claim 12 An image reading apparatus comprising: a line sensor; an image forming optical system for forming an image of an object on said line sensor; and a slit member disposed in an optical path between the object and said image forming optical system, said slit member having a slit and having opening portions at opposite end portions of said slit in a longitudinal direction thereof, said opening portions corresponding to portions outside an effective image region of said line sensor. ### Claim 13 (depends on 12) An apparatus according to claim 12, further comprising means for performing adjustment of said apparatus by moving said slit member on the basis of a result obtained by detecting light passing through said opening portions by said line sensor. ### Claim 14 (depends on 12) An apparatus according to claim 12, wherein said image forming optical system and said line sensor are constituted as a single unit. ### Claim 15 (depends on 14) An apparatus according to claim 14, further comprising means for performing adjustment of said apparatus by moving said unit on the basis of a result obtained by detecting light passing through said opening portions by said line sensor. ### Claim 16 (depends on 12) An apparatus according to claim 12, further comprising means for performing adjustment of said apparatus by moving the overall apparatus on the basis of a result obtained by detecting light passing through said opening portions by said line sensor. ### Claim 17 (depends on 12) An apparatus according to claim 12, wherein a width of each of said opening portions is smaller than a width of said slit in a direction of a shorter side of said slit. ### Claim 18 (depends on 12) An apparatus according to claim 12, wherein a non-opening portion is provided at a boundary between said slit and at least one of said opening portions. ### Claim 19 (depends on 18) An apparatus according to claim 18, wherein opposite ends of said slit in the longitudinal direction thereof have edges which are not parallel to edges of said opening portions. ### Claim 20 (depends on 12) An apparatus according to claim 12, further comprising masking members provided on both end portions of said line sensor in the longitudinal direction thereof. ### Claim 21 (depends on 20) An apparatus according to claim 20, wherein each of said masking members comprises a slit having a width which is smaller than a width of the effective image region of said line sensor in a direction of a shorter side thereof. ### Claim 22 (depends on 12) An apparatus according to claim 12, wherein said line sensor comprises a plurality of reading picture elements.